Correctly forward exception in instance_contains().
Fixes #1591996. Patch contributed by Neal Norwitz.
Will backport.
diff --git a/Lib/test/test_class.py b/Lib/test/test_class.py
index 6c91deb..26b8e7a 100644
--- a/Lib/test/test_class.py
+++ b/Lib/test/test_class.py
@@ -172,6 +172,14 @@
 
 # List/dict operations
 
+class Empty: pass
+
+try:
+    1 in Empty()
+    print 'failed, should have raised TypeError'
+except TypeError:
+    pass
+
 1 in testme
 
 testme[1]